The man stroked nervously at the bridge of his nose. ‘Well – almost, sire. The viscosity is still not quite right.’

‘It’s impressive, nonetheless,’ Lilla offered. ‘Yes. . . And rather horrifying, don’t you think?’ he added, with another nervous pluck at his nose.

‘Isn’t that the point?’

‘Yes. I suppose it is.’ The man’s eyes darted like a bird’s, seeming ill at ease in new company.

‘Go on,’ urged Leo. ‘Tell her how the thing works.’

‘Majesty?’ The fire-maker’s smooth brow crumpled in a frown.

‘Well?’

‘I thought, in light of what you told us two days ago—’

‘What? No! Good God – Queen Lilla is no threat. She’s never even seen an Arab! Go on – explain it to her. Not the detail, man – the principle, the principle!’

‘As you wish, Majesty.’ And so he did, looking decidedly uncomfortable at first, but soon warming to his own expertise and the readiness with which she drank in his every word. It seemed the genius of it was a combination between both the mechanics of the syphon machine and the composition of the liquid itself. But she felt that his explanation left the details deliberately vague.

‘Of course, it’s all rather precise. Any mistakes and. . . well, it doesn’t work.’

‘Fascinating. Still, it must be rather gloomy, working down here, so far from daylight. I feel rather sorry for you.’

‘Nonsense,’ growled Leo. ‘We pay him well enough, I assure you. Besides, it’s his vocation.’

Nikolaos smiled at Lilla. He had a gentle face, pale and sensitive. ‘Your concern is kind, my lady. But the emperor is right. Our father came from Antioch. He lost his lands to the infidel when Syria fell. He never forgot it, nor would he let us forget. I suppose this was his way to take back something of all that he lost.’

‘By burning men to death?’ she said, in a voice innocent as a lamb.

‘By saving an empire!’ Nikolaos blustered. ‘He saved many lives. Saved a way of life.’

‘The city will always honour his name for it,’ said Leo reassuringly.

‘I’m sorry,’ she said. ‘I’ve offended you.’

Nikolaos merely smiled but the wound was plain to see.

‘How can I make it up to you?’

‘There’s no need—’

‘Truly, I must.’

‘Well. . .’ He hesitated, apparently too coy to go on.

‘Please.’

‘I thought that. . . well, it would give me great pleasure if you would call on me. Lord forgive me, but the work down here can be. . . so dull. I should like to hear something of where you’re from.’

Inwardly she smiled. ‘And I should like to tell you.’

CHAPTER THIRTY

Erlan had waited patiently for five days. But tonight, at last, was his opportunity.

He hadn’t wasted the intervening hours. He spent them looking for a foothold – anything that might give him the leverage to bring the siege to a swifter end. And now, perhaps, he had found one.

The Bulgars.